三种厌氧微生物产气的碳同位素特征  

CHARACTERISTICS OF CARBON ISOTOPE OF THE GASES GENERATED THROUGH BIODEGRADATION OF THREE ANAEROBIC MICROBES

作　　者：王万春[1] 宋一涛[2] 徐永昌[1] 沈平[1] 

机构地区：[1]中国科学院地质与地球物理研究所气体地球化学重点实验室,730000 [2]中国石化胜利油田有限公司地质科学研究院

出　　处：《天然气工业》2008年第10期36-40,共5页Natural Gas Industry

基　　金：国家重点基础研究发展规划项目“973”(编号:2002CB211701);中国科学院院长奖获得者专项基金的资助

摘　　要：在咸水和半咸水两种条件下,进行了螺旋藻、马尾藻和松针三种厌氧微生物产甲烷的模拟实验研究,结果表明:在咸水不利产甲烷条件下,CH4和CO2的产率低,δ13C值相对偏轻;而在半咸水较有利产甲烷条件下,CH4和CO2的产率较高,δ13C值相对偏重。反映生化模拟实验中CH4和CO2的δ13C值与其产率有关。在咸水和半咸水两种实验条件下,马尾藻厌氧微生物产甲烷的δ13C值相对于螺旋藻和松针厌氧微生物产甲烷的δ13C值均偏重,可能与马尾藻中高的粗纤维含量有关。厌氧微生物产CO2与CH4的δ13C值之间多不存在相关性,反映模拟实验中甲烷菌生成CH4的途径可能主要为乙酸发酵途径。生化模拟实验中CH4的δ13C值分布范围较宽,介于-19.5‰～-68.3‰,与地质样品中生物甲烷δ13C值普遍低于-60‰的特征不完全符合,表明生化模拟实验由于时间短、有机质的量有限,难以完全重现地质微生物的作用过程,其实验结果仅可作为生物气研究的参考。Experiments of methane production from incubation of anaerobic microbes such as spirulina,sargassum and pine needle are performed under saline and brackish water conditions.The experiment results show that the yields of CH4 and CO2 are small and their δ13C values are relatively low under saline water condition unfavorable for methane generation,while the yields of CH4 and CO2 are relatively large and their δ13C values are relatively high under brackish water conditiions,indicating that the δ13C values of CH4 and CO2 are related with their yields in the anaerobic microbial incubation experiments.In comparison with spirulina and pine needle,sargassum produces methane with relatively heavier δ13C under both saline and brackish water conditions,possibly due to the high content of coarse fibre in sargassum.Most of the δ13C values of CH4 and CO2 produced in the anaerobic microbial incubation experiments have no correlation,indicating that the production of CH4 by methanogens is mainly through acetate fermentation.The δ13C values of CH4 range from-19.5‰ to-68.3‰,which is not entirely in accordance with the δ13C values of geological biogenic methane which are usually lower than-60‰.This shows that the incubation experiments are difficult to reproduce the geological microbial process because of the short time and the limited organic materials and the results of the incubation experiments can be used only as references in the studies of biogenic gases.

关 键 词：螺旋藻 马尾藻 松针 厌氧微生物 甲烷 二氧化碳 碳同位素 特征 

分 类 号：Q935[生物学—微生物学]